Habitat: Gametangial phase epilithic in the sublittoral to 30 m depth. Tetrasporangial phase known only in culture.

Distribution: Widely distributed on western shores of Britain and Ireland, England from the Isles of Scilly, Cornwall, south-west Wales and Scotland including the Shetlands and the Isle of Man. Europe: Mediterranean, Portugal, Atlantic coast of Spain and France. Further afield: Algeria.